Push button



June 3, 1930. B. BOBROFF 1,761,867

PUSH BUTTON Filed April 4, 1923 z sheets-sheet 1 MHH',

A T TORNE Y June 3, 1930. B. BoBRoFF 1,761,867

` PUSH BUTTON Filed April 4, 1928 2 Sheets-Sheet 2 w f? WM' n ATTORNEY*APatented June 3, 1930 UNITED STATES BORNETT L. BOBROFF, OF MILVJAUKEE,WSCONSIN PUSH BUTTON Application. filed April a, 1928.

The invention relates to circuit-closers and more particularly tocircuit-closers of the push-button type. f

An object of the invention is to provide a push-button for use in theindicator-con trolling circuits of a hospital signalling system, and ofysuch construction that the actuation of the push-button will eifect theoperation of switching means movable to successive switching positionsand simultaneously d i s a b l e an indicating means connected incircuit with the switching means, and that the release of thepush-button when the switching means reaches its desired switchingposition will eifect the operation of the indicating means.

Another object of the invention is to provide a push-button for thispurpose including a spring-urged contact-establishing memberalternatively engageable with different contacts, and of such characteras to facilitate and simplify manufacture and assembly.

A further object is to provide a pushbutton including a plurality ofstationary contacts assembled in insulated relation by co-operat-ingattaching members which also form separate terminals for the contacts.

A further object of the invention is to perfect details of constructiongenerally.

rThe invention further consists in the several features hereinafter setforth and more particularly delined by the annexed claims.

ln the accompanying drawings, Fig. 1 is a longitudinal sectional view ofa puslcbutton embodying the invention;

Fig. 2 is a similar view taken on the line 2 2 of Fig. 1;

Fig. B is an end view of the push-button of Fig. 1;

Fig. l is a transverse sectional view of the push-button of Fig. 1 takenon the line -a of Fig. 1;

Fig. 5 is a longitudinal sectional view of another form of push-buttonembodying thc invention Fig. 6 is a similar view taken on the line 6-6of Fig. 5;

Fig. 7 is an en'd view of the push-button of Fig. 5;

Serial No. 257,454.

Fig. 8 is a transverse sectional view of the push-button of Fig. 5 takenon the line 8-8 of Fi 5;

Fig. 9 is a longitudinal sectional view of third form of push-buttonembodying the invention Fig. 1() is a similar view taken on the line10-10 of Fig. 9;

Fig. 11 is an end view of the push-button of Fig. 9;

Fig. 12 is a transverse sectional view of the push-button of Fig. 9taken on the line 12-12 of Fig. 9; and

Fig. 13 is a schematic wiring diagram of a signalling system includingthe push-button of this invention.

ln that embodiment of the invention shown in Fig. 1, the numeral 15designates a cylindrical tubular metal casing, which is adapted to titclosely within a bore 16 formed axially through the pear-shaped endportion 17 of a push-button holder 18, which latter is illustrated indotted outline in Fig. 13 and includes a flat iiidicating portion 19containing a plurality of indicating lamps 20. The push-button holder 18may be of the general type disclosed in United States Patent No.1,367,583, issued to me on Febru ary 8, 1921. The cylindrical casing 15is secured within the push-button holder 18 in any suitable manner, asby means of a tight lit in the bore 16, and is provided with a iiange 21at its outer end engaging the end face of the holder.

An insulating member 22 has a generally circular portion 23 disposedwithin the inner end portion of the cylindrical casing 15 and isprovided with a flanged end 24 which abuts against the inner end of thecasing. The insulating member 22 is held in the casino' 15 in anysuitable manner, as by means of several screws 25 passing throughopenings in the casing and threaded radially into the portion 23 of theinsulating member. The insulating member 22 is provided with a liange'26 at its inner or lower end extending substantially diametrically ofthe insulating member, and a boss 27 is formed on the insulating memberat one side of the fla-nge 26. The boss 27 has an arcuate exterior tting1:00

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within the bore 16 in the push-button holder and is provided withlongitudinallyeextending ley projections 23 which lit within lreyways 29formed in the bore 1G to prevent relative rotation oll the insulatingmember and its attached casing l5 with respect to the push-buttonholder. The cylindrical portion ot the insulating member 22 within thecasing l5 is slightly smaller in diameter than the interior of thel-sing and is surrounded by an insulating sleeve 30, which projectsbeyond the forward end oit the insulating member towards the outer endot the casing. @ne side portion of the insulating member 22 within 'thecasing l5 is ollset to provide a forwardly or upwardly projectingportion having a flat tace lying in a plane normal to the axis ot thecasing, and a Jshaped notch 3l formed at an intermediate portion of this'tace adjacent the inner side of the oitl'set portion, the oii'setportion being disposed on the opposite side of the axis ot' theinsulating member :troni the boss 27. A pair of longitudinally-extendingbores 32 are 'formed through the insulating member 22 on opposite sidesof the notch 3l and terminate at their lower ends in channels 33 whichopen at the rearward or lower ends of the flange 2G and at the,` side otthe liange opposite the boss 7. Bolts 3% and 35 are placed in respectivebores and have llat rectangular heads 3 l and 35 respectively, which titwitl in the channels 33 in the flange 2G and abut against the flangedportion 24 of the insulating member. The threaded upper or forward endsof the bolts 3e and 35 project beyond the forward or upper notched faceof the insulating' member 22, and the bolt 35 is surrounded by a boss 36formed on the lorward or upper end of the insulating member 22 Asegmentally-shaped contact member 37 of llat resilient metal isapertured to receive the bolts 34e and 35 and is disposed against theupper or forward end of the insulating member within the casing, againstwhich tace the contact member is held at one side by a nut 38 threadedon the bolt 3a and also forming an electrical connection between thebolt and contact meniber. Ait the other side of the insulating` member22 the apertured contact member 37 tits about the boss 3G' to properlyposition the Contact member and to insulate it from the bolt 35.

A Ushaped insulating` member 39 of segmental contour has an arcuateexterior litting within the insulating` sleeve 30 and is apertured toreceive therethrough the bolts 3e and 35, the lower or rearward lace ofthe insulating member 39 being provided with recesses l0 and Lll toreceive and provide clearance for the nut 33 and boss 36.

A second segmentally-shaped contact meinber 42, which may be identicalwith the contact member 37, surmounts 'the insulating member 39 and isapertured to receive theretiirough the bolts 341 and 35. The contactmember Ll2 is held against the insulating member 39 at one side by a nuti3 threaded onto t-he bolt 35, which nut also forms an electricalconnection between the bolt 35 and the contact member 42. At the otherside of the insulating member 39 the apertured contact member l2 litsabout a boss ell on the insulating member to properly position thecontact member and to insulate it from the bolt 34. A nut ll5 on theupper and forward end ot the bolt bears on an insulating washer 4G whichengages the contact member 4:2 to clamp the contact member intoposition.

By means of the construction above described, the contact members 37 andl2 are accurately and conveniently assembled and firmly held in spacedrelation within the casing l5, and are also connected in electricalcontact with the bolts 3il and 35 respectively. A. terminal screw i7 isthreaded laterally into the head of the bolt and another terminal screwd8 is threaded laterally into the head ot the bolt suitable clearancespaces being` left within the .flange 26 to receive the ends ot thescrews.

A bore 1ll) is formed in the insulatingmember to extend in parallelrelation to the axis and passes through the boss 2T. A meta-l bushing 50is pressed into the bore llt) and terminates short olI the upper orforward end of the bore to form a shoulder 5l within the bore. A bore 52is formed co-axially in the upper or vloiwvard portions ot the bushing50, and a terminal screw 53 is threaded into the rearward or lower endof the bushing.

'lhe bore in the bushing 50 slidably receives therein the reducedcylindrical end portion 54T ot a plunger stem The major portion ot theplunger stem arranged in parallel relation to the axis ot the casing l5a vd lies adjacent the wall ot the casing. The outer or Aiformird end olthe plunger stem 55 has a portion disposed at the axis ot the casing 15and is provided with a reduced projection 5G which is riveted centrallyof the bottom portion olf a shallow metal cup 57. A circula.v nitton 53,preferably oi' insulating material, is cemented or otherwise secured tothe cup 57 and slidably lits within the outer end portion ot thecylindrical casing l5.

'llhe plunger stem 55 is provided with a laterally disposed projectionoi diamondshaped cross-section extending into a channel or slot (SO'lormed centrally through the insulating member 39 in a directionparallel to tbe axis of the casing l5. The contact members o7 and l2:lose opposite ends of the channel t3() and each is provided with a slittil extending diainetrically with respect to Vthe casing l5, the slitsin the contact inem- Y`ers being arranged to lie in the same plane.

A V-shaped groove is formed on the inner side of Ieach contact memberalong the slit 61 to provide V-shaped contact surfaces with which theopposite knife-edges of the diamond-shaped contact projection 59 arealternatively engageable. The slitting of the contact members provides adegree of resiliency adjacent the contact surfaces in order to insuregood electrical contact with the ycontact projection 59 on the plungerstem.

A coiled spring 62 surrounds the reduced portion 54 of the plunger stemto enter at one end into the bore 49 formed in the insulating member 22where the spring engages the end of the metal bushing 50, and the otherend of the spring engages a shoulder formed on the plunger stem to urgethe plunger outwardly and cause the diamond-shaped projection 59 tofirmly engage the slit portion of the contact member 42. The spring 62also serves to establish an electrical connection between the plungerstem 55 and the metal bushing 50, which latter is provided with theterminal screw 53. The depression of the button 58 by the finger willmove the contact projection 59 within the channel 60 against the actionof the coiled spring 62 and effect the engagement of the contactprojection with 'the slit portions of the contact member 37.

In assembling the push-button, the metal bushing 50 is pressed into thebore 49 of the insulating member 22 and is equipped with the terminalscrew 53. As an alternative, the bushing may obviously be molded inplace in the insulating member. The bolts 34 and 35 are then insertedinto their respective openings in the insulating member with the fiatelongated heads of these bolts lying in the channels 33 in the flange26. It is obvious, however, that as an alternative, these bolts may bemolded directly into the insulating member. rllhe apertured contactmember 37 is then passed over the threaded ends of the bolts 34 and 35,and the nut 38 is threaded onto the bolt 34 to hold this contact memberin place. The insulating member 39 is then mounted in place on the bolts34 and 35 to engage the contact member 37, and the insulating sleeve 30is fitted over the insulating member 22. The coiled spring 62 is theninserted into the bore 49 of the insulating member and the reduced shank54 of the plunger stem is passed through the spring to enter the bore 52in the bushing 50, the contact projection 59 on the plunger stemsimultaneously entering the channel 60 in the insulating member 39. Thecontact member 42 is then passed over the bolts 34 and 35, and the nuts43 and 44 are threaded onto the bolts to effect the engagement of thecontact member with the insulating member 39 against the action of thecoiled spring 62. The spring 62 is thereby placed under compression fornormally retaining the contact i projection 59 againstthe contact member42.

The resultant assembly is then introduced into the tubular casing 15from the rear end thereof and the screws 25 are mounted in place tosecure the insulating member 22 within the casing.

1n the schematic wiring diagram of Fig. 13, a battery or other source ofcurrent `connected by a conductor 76 to the metal bushing 50 receivingthe plunger stem 55 of the push button, the conductor 76 also forming acommon return for the lamps 2O in the push-button holder. The otherterminal of the battery 75 is connected by a conductor 77 leading to oneterminal of an electrical motor 78 which drives a rotary annunciatordrum switch 79, and the other terminal of the motor 78 is connected by aconductor 8O leading to that bolt on the push-button which iselectrically connected to the contact member 37.

The depression of the push-button by the patient effects the engagementof the contact 59 of the plunger stem 55 with the contact member 37 andserves to establish a motor circuit as follows From one terminal of thebattery 7 5, through the conductor 77 electric motor 78, conductor 80,`contact member 37 in the push-button, plunger' Contact 55, conductor 76and back to the battery, thus operating the motor 78 to revolve therotor of the annunciator drum switch 79.

The rotor of the drum switch includes contact ribs 81 which engage withcontactors 82 d uring the rotation of the rotor to establish indicatingcircuits as hereinafter described. A conductor 83 connects one terminalof the battery 75 with one of the contactors 82, and others of thecontactors are connected by conductors 84 leading to indicating lamps85, 86

and 87 placed in various parts of the building, one of these lamps beingplaced at the annunciator and another being placed near the bedside ofthe patient using the push-button holder. These lamps are connected incommon with a conductor 84 connected to the contact member 42 of thepush-button. The remaining contactors 82 are arranged in pairs, one ofeach pair being connected by a conductor 88 leading to a respective lamp2O in the push-button holder 18, and the other of each pair beingconnected by a conductor 89 leading to a corresponding lamp 90 in anindicator 91. The indicator 91 is placed above the door 92 of the roomoccupied by the patient to be visible along the corridor on which thedoor opens. The lamps 90 in the overdoor indicator are connected by acommon conductor 93 which leads to that bolt of the push-button holderto which the contact member 42 is connected.

The motor 7 8 will continue to rotate as long as the push-button is helddepressed by the patient, and in its rotation, the annunciator drumswitch 79 is revolved, preferably in an intermittent manner, tosuccessive switching positions. 1n these switching positions successivecircuits are established including the conductors 88 and indicatinglamps 2O in the push-button holder 18, causing the diilerent lamps 2O tobe successively illuminated, and preferably in an order in Which a Nurseindication is given alternately with every other indication. Thesuccessive illumination of the lamps 2O in the push-button holderindicates to the patient the corresponding switching position of theannunciator drum switch, and when the desired switching position isreached, the push-button is released Which stops the motor 78 and causesthe drum switch to remain in its selected switching position. Therelease of the push-button ettects the engagement of the plunger stein55 with the contact member 42, thus establishing a circuit including thebattery 75, conductors 77 and 83, connected contacter 82, contact ribs81, others of the contactors 82 connected to the conductors 84, throughthese conductors and the lainps 85, 8G and 87, conductor 841- andconnected contact member 42 in the push-button, plunger 55, andconductor 76 back to the battery. Lamps 85, 86 and 8'? will then becomeilluminated, one of these lamps being at the annunciator and anotherbeing in the same room With the push-button holder. At the same timeanother circuit will be established including that contacter 82 which isone ot the pair of contactors connected to the active conductor 88,through the conductor 89, lamp 90 in the over-door indicator effectingthe same indication as that present in the push-button holder, conductor93, contact member 4t2 in the push-button, plunger 55, and conductor 7Gback to the battery, thus illuminating that lamp 9G in the over-doorindicator Which corresponds to the lighted lamp 2O in the push-buttonholder. The nurse on duty in the corridor Will observe the htedindicating lamp 90 in the over-doei nxlicator and thereupon attend tothe Wants ot the patient. lVhen the nurse responds to the signal shedepresses another push-button 9-1 placed in the room near the patientsbedside, Which operation serves to momentarily establish a motor circuitcausing the motor 78 to operate and return the annunciator drum switchto its succeeding blank position, Where no indicating circuits areclosed.

By reason of the back contact L12 in the push-button, it Will be seenthat all lamp circuits including those in the over-door indicator, andexcepting only those including the lamps 20 in the push-button holder,are broken as long as the push-button is held depressed, so that allindicating lamps With the exception of those in the push-button holderWill remain dark until the patient releases the push-button upon thearrival of the desired signal in the succession. 1n this Way,unnecessary and undesirable flashing of light in the corridor, on theannunciator board and elsewhere, will be avoided.

1n the niodilied iorm of push-button shown in Figs. 5 to 8 inclusive, aflanged cylindrical casing 115 is generally similar to the casing 15 ofthe F 1 device and includes key-projections corresponding in iunction tothe projections 28 on the insulating member 22 ot the Fig. 1 device. Aninsulating member 122, generally similar to the insulating member 22 oi"the Fig. 1 device, is introduced into the casing 115 and is securedtherein in a similar manner. An insulating sleeve 130, similar to theinsulating sleeve 80, of the Fig. 1 device, is interposed between theinsulating member and the casing. The portion of the insulating member'122 projecting into the casing includes an oll'set portion which dividedcentrally by a radially-extending slot 181. A pair oi" spaced parallelbolts 13stV and generally similar in character and ydisjnisition to tuebolts Ji-:l and ot the Fig. 1 device, extend through the insulatingmember on opposite sides ot the slot 131 and incluoe head portions 131and 185, respectively, which .lit Within recesses in the insulatingmember. Terminal screws 14T and 148 are threaded axially into these boltheads. The upper threaded portions ot the bolts 134s and 135 passthrough contact members 137 und 142 and an interposed insulating member139. 'lhese latter parts are generally similar to the parts Si', and 39or the Fig. l device. and are assembled on the bolts 18st and 135 in asubstantially identical manner.

A bore 152, corresjmnding in function and position to the bore 52 of the1 device, is formed in the insulating member 122 and slidably receivestherein the reduced cylindrical end portion ot a plunger stem 155 whichis substantially identical in construction and disposition with theplunger' stem 55 oit' the Fig. 1 device. The plunger stem 155 hassecured thereto a circular button 158 which may be identical incharacter and disposition with the button ot the Fig. 1 device.

The plunger' stein 15; is provided With a contact projection 159 ofdiamond-shaped cross-section extending into a channel or slot 160 iormedin the insulating member 189 to be placed in alternative engagement withthe contact members 187 and 142 in a relation similar to that in theFig. 1 device.

A coiled spring 102 similar in lunction to the coiled spring 62 ot the F1 device surrounds the reduced portion of the plunger stem and includesa part extending into the slot 181 Where it is secured to the 'threadedend portion ot a bolt 150 which extends through the insulating member122 near the outer edge thereol in parallel relation to the axis ot theinsulating member. rllhe outer end of the insulating bolt .150 exten dsthrough a boss 127 projecting from the end of the insulating member toprovide ample separation between the head of the bolt 150 and the tei'-minal screws 147 and 148 ot the bolts 134 and 135. The head ot the bolt150 is disposed within a. recess in the end vofthe boss 127 and isprovided with a termina-l screw 153.

In assembling the push-button, the se- Iquence oi' operation isgenerally the same as that employed inthe assembly ot the pushbutton ofFig. 1. The bolts 134, 135 and 150 may either be introduced throughbores in the insulating member 122 or they may be molded directly intothe insulating` member.

In the modiiied 'form ot push-button shown in Figs. 9 to 12 inclusive,the numeral 215 designates a cylindrical tubular metal casing generallysimilar to the casing 15 ot the Fig. 1 device, secured within the bore16 .in the pear-shaped end ot the push-button holder in any suitablemanner. A U-sliaped insulating member 239 generally similar to theinsulating member 39 of' the Fig. 1 device is secured within the casing215 at an intermediate por- 'tion ther-cot by means oi screws 245. Thecontact men'iber 242 is secured to the upper 'lace ot this insulatingmember by means ot a screw 235 and is hel-d in its proper position meansot' lugs 244 entering recesses in the insulating member'.

An insulating member 222, generally similar to the insulating member 22ot the Fig. 1 device, tits within the cylindrical casing 215 and is heldtherein by means ot screwsY 225. A contact member 237 is secured to theupper tace ot the insulating member 222 by means ot a screw 234, and anotch 231 is formed in the upper f e ot the insulating` member toprovide clearance for portions of the contact member 237. The Contactmembers 237 and 242 are slit a manner similar to the Contact members'37. and `42 ot the Fig. 1 device to provide IV -shaped contact surfaces.

guide opening 252, corresponding in `tunctionA 'and position to the bore52 of the Fig. 1 device, is formed inthe insulating member 222 andslidably receives therein the reduced end portion ot a plunger stem 255which is generally similar' in construction and disposition to theplunger stem 550i1 the Fig. 1 device. The plunger stem 255 has securedthereto a circular button 258 which may be identical in character anddisposition to the button 58 in the Fig. 1 device.

The plunger stem 255 is provided with a contact projection 259 ofdiamond-shaped cross-sccti on extending into a channel or slot 26()formed in the insulating member 239 to be placed in alternativeengagement with the contact members 237 and 242 in a relation similar tothat in the Fig. 1 device.

A coiled spring 262 similar in function to the coiled spring 62 ot theFig. 1 device snrrounds the reduced portion ot the plunger stem andincludes a part extending through the insulating member 222 and securedto a terminal screw .253 threaded into the insulatinjg member. rPhespring thus serves to establish an electrical connection between theplunger stem and this terminal screw. The Contact portion 259 of theplunger stem is urged by the spring into engagement with the contactmember 242 and the depression of the button 258 by the iinger will movethe Contact projection 259 against the action of a spring to effect theengagement ot the contact projection with the contact member 237.

The insulating member 222 is provided with a flange 226 at its inner orlower end eX- tending substantially diametrically ot the nsulatingmember. ril,`e|1ninal screws 247 and 243 are threaded into oppositesides of the 'flange 226 and are connected respectively with the Contactmembers 242 and 237 by means ot conductors 238 and 243.

In assembling the push-button ot Fig. 9, the insulating` member with itsattached Contact member 242 is secured within the casing 215 by meansoit the screws 245. The plunger stem is then introduced into thecasingtrom above and turned sutiiciently to permit the contact projection topass the contact member 242 subsequent to which the contact projection259 is introduced into the channel or slot 260. The insulating member222 with its attached member 237 and spring 262 is then introduced intothe inner end oit the casing and is secured therein by the screws 225.In this assembly operation, the coiled spring 262 is passed over thereduced end portion ot the plunger stem 255 and the spring is placedunder compression to urge thel contact projection 259 in iirm engagementwith the contact member 242. rlhe contactmember 237 lies in closerelation to the insulating vmember 239 and is placed in proper positionto be engaged by the contact projection 259 when the plunger' stem 255is depressed. y

rlhe invention provides a push-button of simple, compact and durableconstruction capable ot inexpensive manufacture and wellr adapted :torits intended purpose.

That I claim as new and desire to secure by Letters Patent is:

1. In a puslrbutton, the combination of a casing, an insulating membermounted witlr in the casing, a pair ot contacts disposed on oppositesides ot said insulating member and spaced axially within the casing, acontactor movable between said contacts into selective engagementtherewith and normally spring urged into engagement with one ot saidcontacts, said contactor having an actuating part at one end of saidcasing, and a second insulating member carried at the other end ot thecasing and havinga recess in which said contactor is slidably `guided.

2. In a push-button, the combination of a pair of spaced contactsinsulated from each 'other9 supporting means tor said contacts includinga separable insulating member interposed therebetween, attaching membersfor securing said contacts to said insulatingl member and respectivelyhaving electrical connections with said contacts, a contactor includinga portion interposed between saidI contacts for selective engagementtherewith and being normally spring-urged into engagement with oneotsaid contacts, and means for movably supporting said contactor.

3. In a push-button, the combination of an insulating member, contactsdisposed on opposite sides of .said insulating member in insulatedrelation, a second insulating member, attaching members mounted in saidsecond insulatirm` member and passing through said contacts and thefirst-named interposed insulating member to secure said contacts inposition and to form respective electrical connections with saidcontacts, and a cont-actor slidably guided in said second-namedinsulating member and having a portion interposed between said contactsfor selective engagement therewith and being normally spring-urged intoengagement with one of said contacts.

4. ln a push-button, the combination ciE a apertured insulating member,a pair of apertured cont-acts disposed on opposite sides ot saidinsulating member in insulated relation with the apertured portions otsaid contacts and insulating' member in register, a second insulatingmember, a pair of attaching members mounted in said second-namedinsulating member to project therethrough and bavi ng their projectingportions passing through said contacts and the iirst-named interposedinsulating member for holding said contacts in insulated assembledrelation, and a contactor slid ably mounted in said second-namedinsulating member having a portion interposed between said contactmembers for selective engagement therewith and being normallyswing-urged into engagement with one oi said Contact members.

5. In a j iush-button, the combination oit an apertured insulatingmember, a pair ot apertured contacts disposed on opposite sides of saidinsulating member in insulated relation with the apertured portions ofsaid contacts and insulating member in register, a second insulatingmember, a pair of attaching members mounted in said second-namedinsulating member to project therefrom and having their projectinportions passing` through d contacts and the first-named interposedinsulating member tor holding said contacts in insulated assembledrelation, a shouldered contactor slidably mounted in said secondnamedinsulator member and having a portion interposed between the contactsfor selective engagement therewith, and a spring interposed between saidsecond-named insulating member and the shouldered portion of saidcontactorl for normally urging said con.- tactor into engagement withthe contact more remote from said second-named insulating member.

6. In a push-button, the combination, with a hollow casing, of aninsulating member adapted to be introduced into said casing, a pair ofinsulated Contact members spaced axially within said casing, attachingrmembers securing said contacts to said insulating member and formingterminals therefor, a plunger movably mounted in said insulating memberand spring-urged outwardly therefrom, said plunger including alaterallyprojecting contact portion interposed between said contacts torselective engagement therewith and normally urged into engagement withone ot said contacts, an actuating member tor said plunger movablewithin the outer end of said casing, and terminal means for said plungercarried by said insulating member.

7. In a push-button, the combination, with supporting members, of a pairof recessed sheet metal contacts disposed in substantially parallelspaced relation and presenting aligned contact surfaces at theirrecessed portions, a nianually-displaceablc contactor interposedbctwerrn said contacts tor selective engagement therewith and includingopposite contact edges adapted to enter said rccesscd portions. meansYfor movably supporting said contactor in its operative position, andspring means tor normally urging said contactor into engagement with oneof said contacts.

8. In a push-button, the combination, with a casing, ot an insulatingmember projecting into said casing and having an exterior flangedportion, attaching members secured within said insulating member andincluding terminal portions within said flanged portion ot theinsulating member and projecting portions at the opposite side of saidinsulating member, a pair of contacts secured in insulating spacedrelation on the projecting ends of said attaching members, a manuallydisplaceable contactor movably mounted on said insulating member andincluding a portion interposed between said contacts for selectiveengagement therewith, and spring means normally urging said contactorinto engagement with one of said contacts.

9. In a push-button, the combination ot' a support, a. sheet metalcontact plate mounted on said support and having a slit presentingcontact surfaces therealong, and a movably mounted contactor including aportion adapted to enter said slit and engage said contact surfaces.

l0. In a push-button, the combination of a support, a resilient sheetmetal. contact plate mounted von said support and having a slit formingspaced resilient lips presenting Contact surfaces therealong, and amovably mounted contactor having wedge portions adapted to enter saidslit and engage said resilient lips.

11. In a push-button, the combination of an insulating member, a metalplate seeured to said insulating member and having,` a slit forming apair of contact surfaces therealong, and a movably mounted contacterhaving a Wedge-shaped port-ion adapted to enter said slit and engagesaid contact surfaces.

l2. In a push-button, the combination of an insulating member havingopposite Jfaces and a recess extending between said faces, contaetplates mounted on the opposite 'faces of said insulating member andpresenting Contact portions in alignment With said recess, and a movablymounted eontactor disposed Within said recess and selectively engageableWith the Contact surfaces atthe opposite ends of said recess.

ln testimony whereof, I ailix my signature.

BORNETT L. BOBROFF.

